"Rak Haeng Siam" centers around two boys and their families who live as neighbours in one of the suburbs of Bangkok. We meet them the first time when they're about 12 years old. Mew (Artit Niyomkul) is a stubborn kid who lives with his ailing grandmother (Pimpan Buranapim) and is a bit of a loner. Tong (Jirayu La-ongmanee) is an energetic boy who lives with his parents and sister. After accidentally spitting gum into Mew's hair, Tong wants to befriend Mew but is rejected. At school Mew is cornered by several other students who harass him until Tong comes to his defense. Tong was injured and apoligizes to Mew for the chewing gum incident. The two become good friends. Mew plays on his grandfather's (Surapol Chonwilai) piano and is joined by his grandmother. Mew asks her why she likes a certain song and she says his grandfather expressed his love for her with it and one day Mew will be able to do the same for the person he loves.
Tong's family goes to Chiangmai in the north of the country and returns without Tong's sister Tang (Laila Boonyasak), since she wants to stay with her friends a few days more. Tang calls her parents and tells them that she will extend her stay at Chiangmai until the 24th of December. Tong realizes that Tang will not be able to attend the Christmas play he is in. After the play, Tong receives a phone call from his parents telling him to stay with Mew and his grandmother. After spending the night at Mew's house, Tong awakens to see his parents along with Mew and his grandmother. His parents are going to Chiangmai to look for Tang who is missing on a trekking tour in the jungles around Chiangmai. Tong is depressed until his parents come back, only to learn that Tang may be lost. He is devastated and cries in front of Mew, who comforts his friend.
Months pass and Tong's family decides to move. On the day of the move, Tong finds Mew sitting on a ledge overlooking a pier. Tong says his final words and departs in a car, looking back to see Mew walking towards the car before coming to a stop and crying about losing his best friend.
Six years pass. The boys are reunited during their senior year of high school at Siam Square. The musically talented Mew (Witwisit Hiranyawongkul) is the leader of a boy band called August. Tong (Mario Maurer) has a pretty girlfriend, Donut (Aticha Pongsilpipat). The meeting stirs up old feelings of love for Tong. Mew's band has a new manager, June (Laila Boonyasak), who looks just like Tong's long-lost sister. After meeting June, Tong and his mother Sunee (Sinjai Plengpanit) devise a plan to pay June to pretend she is Tang, in hopes that it will pull Tong's father out of his alcoholic depression. Tang borrows a story from the Thai film "Ruk Jung", saying she has amnesia, which is why she has forgotten how to say her family's Catholic grace at the dinner table.
Mew is also the object of an unrequited crush of a neighbor girl, Ying (Kanya Rattapetch). But Mew has strong feelings for Tong, which has inspired him to write new songs. The manager as well as the entire band are impressed with Mew's compositions. The boys share a prolonged kiss in Tong's backyard one night after a party in honor of the return of Tang. Prior to that Tong also spends the night with Mew, which causes his mother to worry.
At Christmas time, as Tong and his mother are decorating a Christmas tree, they have a heart-to-heart talk about making choices, and Tong asks his mother to let him make his own choices. Tong then goes to Siam Square for a date with Donut. Mew's band is playing nearby, so Tong abandons Donut and tells her he cannot be with her. He rushes to see Mew play and is guided there by Ying, who has accepted the fact that Mew loves Tong. After the performance, Tong gives Mew a gift, a missing nose from a wooden doll that Tong gave him when they were children. However, Tong tells Mew he cannot be his boyfriend but that doesn't mean he doesn't love him. Mew puts the missing nose back on the wooden puppet, says "thank you" and quietly cries. The ending is ambiguous and begs for a sequel.
This movie is a sincere and convincing story about family ties and different kinds of love. It could have been a TV soap opera because it has several parallel subplots with weird twists. The performances of most actors, especially the pair in love, is realistic, balanced, and not melodramatic. When the film was shown on Thai TV the pivotal scene with the two boys kissing was omitted. Director Chookiat Sakveerakul admitted the film was marketed as a straight romance because he wanted it to reach a wider audience. "The movie is not all about gay characters, we are not focusing on gay issues, we are not saying, "let's come out of the closet", so obviously, we don't want the movie to have a gay label," he said in an interview. He may have been right in his tactics: by tricking the audiences he made them watch a different reality which isn't that different from their own.
"Rak Haeng Siam" was received with critical acclaim upon its release. Bangkok Post film critic Kong Rithdee called the film "groundbreaking", in terms of being the first Thai film "to discuss teenagers' sexuality with frankness". Nattakorn Devakula wrote, "The point that the film attempts to teach viewers--and a largely conservative Thai society--is that love is an evolved form of emotional attachment that transcends sexual attraction of the physical form." However, Gregoire Glachant of BK magazine wrote "The Love of Siam isn't a very well shot movie. Chookiat's camera only records his dull play with equally dull angles and light as it wanders from homes to schools, to recording studio, and to Siam Square without sense of purpose or directions." Kitti Kuremanee composed the music, and Chukiat Sakveerakul wrote the screenplay and directed. In Thai with English subtitles. The English titles are "Rak Haeng Siam" and "The Love of Siam".
